Center-pivoting bed



Aug. 29, 1969 A. MOR ISON CENTER-PIVOTING BED 2 Sheets-Sheet 1 FiledAug. 11, 1967 EAR LE MORRISON Agent Aug. 29, 1969 E. A. MORRISONCENTER-PIVOTING BED 2 Sheets-Sheet. 2

Filed Aug. 11, 1967 FIG. 5 3

E' xwsaaem 454, I ZJ Agent United States Patent Olfice 3,462,772CENTER-PIVOTING BED Earle A. Morrison, 3490 Cypress St., Vancouver 9,British Columbia, Canada Filed Aug. 11, 1967, Ser. No. 659,920 Int. Cl.A61g .7/ US. Cl. 63 6 Claims ABSTRACT OF THE DISCLOSURE A bed having abase and a vertically displaceable mattress-supporting frame which ispivoted at its mid-point to one end of a connecting arm of which theother end is pivoted to the base. Means are provided for keeping theframe in a horizontal position while being lowered or raised, but thismeans can be selectively disconnected from the frame to allow the latterto assume an angular orientation.

This invention relates to a bed of which the mattresssupporting frame isadapted to be raised and lowered with respect to the floor, and whereinthe frame, at any vertical position, can be tilted to place the head-endeither above or below the foot-end. The bed to which this inventionrelates is particularly suitable for use in hospitals.

The object of this invention is to provide a bed of the above type,simple in construction and easy to operate.

Accordingly, this invention provides a bed, comprising: a base, a framefor supporting a mattress above said base, a connecting arm mounted atone end to said base to pivot in a vertical plane about a first axis,said frame being mounted at substantially its mid-point to the other endof said connecting arm for pivotal movement with respect thereto about asecond axis parallel with the first axis, means for pivoting saidconnecting arm about said first axis to raise and lower said frame, andmeans for maintaining said frame in a horizontal orientation duringraising and lowering of said frame.

Two embodiments of this invention are shown in the accompanyingdrawings, in which like numerals denote like parts throughout theseveral views, and in which:

FIGURE 1 is a partly broken-away perspective view of a portion of thebed in accordance with this invention;

FIGURE 2 is a partly broken-away perspective view, to a larger scalethan FIGURE 1, of one portion of the bed of FIGURE 1;

FIGURE 3 is a partly broken-away perspective view of another portion ofthe bed of FIGURE 1;

FIGURE 4 is a view similar to FIGURE 3, to a smaller scale, showing analternate construction; and

FIGURE 5 is a schematic elevational view of the bed of FIGURE 1 showingthree diiferent orientations that the mattress-supporting frame iscapable of assuming.

Turning first to FIGURE 5, the bed of this invention is seen to comprisegenerally a base 11, a frame 12 for supporting a mattress above the base11, a connecting arm 14 mounted at one end 16 for piovtal movement in avertical plane parallel with the long dimension of the bed 10, andconnected at its other end 17 to the frame 12 at approximately themid-point of the latter. Means, later to be described, are provided forcausing the connecting arm 14 to pivot about its end 16, and furthermeans are provided, selectively operable, to cause the frame 12 toremain in a horizontal position during elevation and lowering. Theselatter means can be disconnected in order to permit the frame 12 toassume an angled position as shown at 18 in FIGURE 5.

Attention is now directed to FIGURE 1 which shows, in perspective, partof the base 11, the frame 12, the means by which the latter is raisedand lowered, and the 3,462,772 Patented Aug. 26, 1969 means by which theframe 12 is kept in a horizontal position during raising and lowering.

The base 11 includes a hollow rectangular member 20, connected at eitherend to T-bars 21 and 22, both of which are supported on a pair of castorwheels 23 (only two of the four wheels 23 visible).

In FIGURE 1 the connecting arm 14 is shown to have a width comparable tothe width of the frame 12, and is pivoted about a shaft 24 to the T-bar22. At the end 17 of the connecting arm 14 is pivotally mounted a shaft25, which is not visible in FIGURE 1, but which can be seen in FIGURE 2.The shaft 25 is secured at either end to the frame 12 by means of plates26 (only one such plate 26 visible in each of FIGURES 1 and 2). Theconnection between the shaft 25 and the frame 12 is at substantially themid-point of the latter, such that the frame 12 can be easily pivotedaway from the horizontal posi. tion, when and if this should becomenecessary.

The raising and lowering of the frame 12 is accomplished by means of afurther connecting arm 28, and a hydraulic cylinder 30 (shown in dottedlines in FIGURE 1). The connecting arm 28 is pivoted at its upper end 31about the shaft 25, and is thus pivoted to the upper end 17 of theconnecting arm 14. The lower end of the further connecting arm 28 isbifurcated into two arms 33 and 34, which constitute a kind of clevisbetween which a clevis pin 36 extends. The clevis pin 36 is adapted toslide in a pair of slots 38 (only one visible) in the member 20 of thebase 11. The right hand end 40 of the hydraulic cylinder 30 is fixed tothe base 11, and the piston rod 41 of the hydraulic cylinder 30 issecured to the clevis pin 36. Thus, extension and retraction of thepiston rod 41 causes the connecting arms 14 and 28 to geniculate,thereby causing the frame 12 to be raised and lowered.

The means by which the frame 12 is maintained in a horizontalorientation during its raising and lowering will now be described withreference to FIGURES 2 and 3 of the drawings.

Referring to FIGURE 2, a short tubular element 42 is mounted rotatablyabout the shaft 25. In FIGURE 1, element 42 is shown in its assembledposition, adjacent the side of the frame 12. A further identical tubularelement 42 is located at the opposite end of the shaft 25 adjacent theother side of the frame 12, but it is partly hidden by the frame 12.Each tubular element 42 has, at one end, a flange 44 rigidly securedthereto. The flange 44 has a plurality of radial slots 45 for a purposeshortly to be described. At the other end of each tubular element 42 arerigidly secured two pinion members 46. The T-bar 22 has two upstandingprojections 48, of which one is visible in FIGURE 3. The shaft 24 aboutwhich the connecting arm 14 pivots passes through the projections 48.Rigidly secured to each projection 48 is a further pair of pinionmembers 50 identical to the pair 46 of pinion members. Thus, theconnecting arm 14 may pivot about the shaft 25 while the pair 50 ofpinion members remains in fixed relation with the T-bar 22. An endlesschain 52 is tightly engaged around both pairs 46 and 50 of pinionmembers such that the pinion members 46 always remain in the sameorientation, regardless of the angular position of the connecting arm14. That is to say, the uppermost spoke or tooth of one of the pinionmembers 46 will always remain the uppermost tooth, regardless of theangular position of the connecting arm 14.

In FIGURE 1 is shown a release bar 54 pivoted to the frame 12 at twopivot points 55, of which one is visible in FIGURE 1. Connected at 56 tothe release bar 54 is a rod 58 which runs parallel with the frame 12 andpasses through a bracket 60 attached to the frame 12. The rod 58 has awedge-shaped end 61 and a flange 62 (see FIG- URE 2). A compression coilspring 64 is compressed between the flange 62 and the bracket 60,thereby urging the rod 58 to the left. When the tubular element 42 shownin FIGURE 2 has been slid along the shaft 25 to its proper positionimmediately adjacent the frame 12, the wedge-shaped end 61 on the rod 58is adapted to engage in one or the other of the radial slots 45 in theflange 44. Because the flange 44 always maintains the same orientationregardless of the position of the connecting arm 14, it is possible tolock the frame 12 in a horizontal position, maintained throughout itsraising and lowering, merely by engaging the rod 58 into the appropriateone of the radial slots 45. FIGURE 1 shows this engagement. There is,preferably, another rod 58 along the opposite nearer side of the frame12, engaging with the flange on the other tubular element, but none ofthis is visible, being hidden by the frame 12 itself.

If it is desired to release the frame 12 from its locking relation withthe flange 44, the operator merely pushes downwardly on the release bar54, thereby retracting the wedge-shaped end 61 from engagement with theflange 44, releasing the frame to pivot about the shaft 25. The operatorcan then, if desired, place the frame 12 in, for example, theTrendelenburg position, for which another slot 45 is provided in theflange 44. Pressure on the release bar 54 is then relaxed, therebyletting the wedge-shaped end 61 move to the left and engage theappropriate Trendelenburg slot.

FIGURE 4 shows an alternate construction for assuring that the flange 44always remains in the same orientation during the raising and lowering.Instead of the sprockets 46 and 50 and the chain 52, there is providedon the T-bar 22 an upstanding member 66 having two wings 67 disposed atapproximately a 45 angle to the horizontal. Two similar wings 68 arefixed to the tubular element 42. Two parallel rods 70 extend betweencorresponding wings, as shown. Each rod 70 is pivotally connected ateither end to a wing 67 and a wing 68, and the length and direction ofthe line extending between the pivot axes of either rod are at all timesthe same as the length and direction of the line extending between thepivot axes of the connecting arm 14. It will be appreciated that one ofthe rods 70 could be dispensed with without impairing the operation.Furthermore, the angle 45 is not critical. The pairs of wings could, forexample, extend roughly vertically.

Although a hydraulic cylinder 30 has here been shown as the means bywhich the frame 12 is raised and lowered, those versed in this fieldwill be aware that other means, such as an electrically or manuallyoperated mechanical screw or a ratchet, could also be employed for thispurpose.

What I claim as my invention is:

1. A bed comprising:

a base,

a frame for supporting a mattress above said base,

a connecting arm mounted at one end to said base to pivot in a verticalplane about a first axis,

said frame being mounted at substantially its midpoint to the other endof said connecting arm for pivotal movement with respect thereto about asecond axis parallel with the first axis,

means for pivoting said connecting arm about said first axis to raiseand lower said frame,

and means for maintaining said frame in a horizontal orienttion duringraising and lowering of said frame, said last-mentioned means formaintaining including: a first pinion member secured to said base andcoaxial with said first axis, a second pinion member mounted forrotation coaxially with said second axis, the two pinion members havingthe same diameter,

an endless, flexible member engaged tightly around both pinion members,and

means for selectively locking said frame to said second pinion member.

2. A bed as claimed in claim 1, in which said endless flexible member isa chain, and in which said pinion members are spur gears adapted toengage with said chain.

3. A bed as claimed in claim 1 in which said means for pivotingcomprises:

a further connecting arm having its one end pivotally connected to saidfirst-mentioned connecting arm at a location spaced from said firstaxis, and its other end slidable horizontally toward and away from saidfirst axis, such that movement of the other end of said furtherconnecting arm toward said first axis causes said frame to rise relativeto said base.

4. A bed as claimed in claim 3, in which a hydraulic cylinder providedin said base is operable to move said other end of said furtherconnecting arm toward and away from said first axis.

5. A bed comprising:

a base,

a frame for supporting a mattress above said base,

a connecting arm mounted at one end to said base to pivot in a verticalplane about a first axis,

said frame being mounted at substantially its mid-point to the other endof said connecting arm for pivotal movement with respect thereto about asecond axis parallel with the first axis,

means for pivoting said connecting arm about said first axis to raiseand lower said frame,

and means for maintaining said frame in a horizontal orientation duringraising and lowering of said frame, said last-mentioned means formaintaining including:

a member mounted for rotation coaxiaily with said second axis andcarrying a first pivot remote from said second axis,

a second pivot fixed with respect to said base, the second pivot beingspaced from said first axis the same distance as separates said firstpivot from said second axis, and

an elongated rigid member pivoted at one end to said first pivot and atthe other end to said second pivot, the elongated rigid membermaintaining the first and second pivots apart the same distance asseparates said first axis from said second axis.

6. A bed as claimed in claim 5, in which said means for pivotingcomprises:

a further connecting arm having its one end pivotally connected to saidfirst-mentioned connecting arm at a location spaced from said firstaxis, and its other end slidable horizontally toward and away from saidfirst axis, such that movement of the other end of said furtherconnecting arm toward said first axis causes said frame to rise relativeto said base.

References Cited UNITED STATES PATENTS 2,471,90l 5/1949 Ross 254-93,200,416 8/1965 Warrick 562 3,201,806 8/1965 Hutt 5-62 3,203,670 8/1965Farris 254-122 3,284,815 11/1966 Grossman et al. 5-62 3,308,485 3/1963Evans 563 CASMIR A. NUNBERG, Primary Examiner U.S. Cl. X.R.

